A 10cm3 sample of copper has a density of 897g/cm3. What is the mass of the sample?

A 10cm³ sample of copper has a density of 897g/cm³. What is the mass of the sample ?

Density of sample of copper is 897g/cm³.

Volume of sample of copper is 10cm³.

The mass of the sample.

We know,

So, Mass = 897g/cm³ × 10cm³

Mass = 8970 g

Far point = 202 cm

Near point = 38.5 cm

Explanation:

For distance vision we know that

we know that

now by lens formula we know that

so we have an object positioned at infinite we have

now distance from eye is given as

Now similarly for near point given at 25 cm from eye

the distance of the image should be 25 - 2 = 23 cm

power for near point is given as

now again by lens formula